Sand-blast apparatus



Jan. 3%; 3923.

C. 6. SMITH. SAND BLAST APPARATUS 2 SHEETS SHEET I FILED JUNE 10, 1921.

f'werdon Charles G. Jmzlilg.

2 SHEETS-SHEET 2 rney.

.ZhUGRZOr: Charms G Smith,

Jan. 30, 1923.

c. 0. SMITH.

SAND BLAST APPARATUS.

FILED Juws I0. 1921.

Patented 30, 1923.

UNETEEE CHARLES G. SMITH, OF PHILADELPHIA, PENNSYLVANIA,

SAND-BLAST Application filed June 10,

T 0 oil who/a '1' t may concern.

Be it known that I, CI-IAnLns G. SMITH, a citizen of the United Statemresiding at Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented certain new and useful Improvements in SandBlast Apparatus, of which the follow ing is a specification.

My invention relates to sand blast apparatus, and it relates more particularly to an improved form of pressure tank and the as sociated parts, including the hopper and the means for permitting the sand to pass from the hopper to the tank. Heretofore, the common type of sand blast apparatus comprised. among other parts, the provision of a tank in which the supply of sand was kept under pressure. In the base of the pressure tank, there was usually provided a sand trap, by means of which the sand was permitted to pass into a current of air to be conveyed,- through suitable piping and hose, to the outlet nozzle. The pressure tank was also provided at the top with a funnel-like hopperinto which the replenishing supply of sand was either placed or was permitted to fall after being used, a valve being provided between the hopper and the pressure tank, which valve closed the tank when the sand was being used therefrom, but which was opened when it was necessary to permit a fresh supply of sand to pass from the hopper into the pressure tank. In the operation of the valve of the type most commonly used, it frequently occurred that when nails and other foreign objects would become mixed with the sand in the hopper, the same would choke the valve, not only preventing the sand from passing to the pressure tank, but also preventing the closing of the valve when it was desired to resume the use of the sand from the pressure tank. The operating mechanism of such valves was also 10- sate-d within the h pper, being surrounded the sand in the hopper, which arrangenient resulted in rapid destruction of the parts by reason of the sand getting into the working parts of the valve and its operating mechanism.

The object of my present invention is to provide an improved forinof pressure tank and its associated parts for sand blast apparatus, in which the sand will have a clear passage from the hopper to the interior of the pressure tank whenthe valve is open,

which will be so constructed and arranged as APPARATUS.

1921. Serial No. 478,624.

to reduce to a minimum the likelihood of foreign substances obstructing the'passage' ..struct and arrange the pressure tank and its associated parts whereby certain conveniences and economies in the'operation of the same will be effected, as will hereinafter more fully appear. A further object of my invention is to provide an improved form of automatic means for relieving the pressure within the tank when the valve is open to permita fresh supply of sand to pass from the hopper to the interior of the pressure tank. A further object of my invention is to provide means for introducing an auxiliary regulatable supply of air to the pipe line for the delivery of the mixture of air and sand, whereby the relative quantities of the air and sand may be more readily controlled for the purpose of effecting a more eflicient action of the apparatus.

The nature and characteristic features of my invention will be more readily understood from the following description, taken in connection with the accompanying drawings forming part hereof, in which Figure 1 is a side elevation, partly in section, of a pressure tank and its associated parts for sand blast apparatus, embodying the main features of my present invention;

Fig. 2 is a top or plan view thereof, with the hopper removed; and

Fig. 3 is an enlarged sectional detail view more clearly illustrating the construction of the valve and the adjacent parts.

Referring to the drawings, in the particular embodiment of my invention therein shown, 5 is the pressure tank, preferably made of sheet metal and of cylindrical form with a conical base 6, at the bottom ape); of which a sand trap 7, of the usual construction, is mounted. The top plate 8 of the pressure tank 5 is provided with a centrally arranged pipe: flange 9 bolted thereto, and in said pipe flange 9 there is mounted a; valve trance of the sand into the pressure tank 5. A flange member 12 is secured to the top of the housing and forms a support for a was (-onizal hopper l3, hair :1 th ont or opening ill at the base th reof of? a danietw' than that of the central p the alrc housing UL; u hereinaitor explained.

The housing it i side. w t permit th: 1

p oi a valve gate 36, 2h of which is ol" semi-circular coi shaped in cross section. the yalrc i1()ll5lllg hi, on the side t posite the slot l5. there is pi'orid annular groore l-fl in which gasket 19 t rubber or similar re teriah so that mien the ralre 7 pushed inward to close the tl'iroupgh the valve l'icuising- 19 will prevent the passage pressure within the tank of the valve housing 10, bethe slot there groove 20, in which gasket 2!, and the salve gate 16 1 on its under side with a inen'iber inountci' is so lotated wit-ii respect to the me? of the Valve gate 16 that when the is pushed inward to its close-z irdnt cud L I; oi? the extension et it and thereby urei'i age irou'i .ielou' the urulcr valve gate when the same is closed.

The rear end oi? the val i'ided .vith u cylinc lb 2s protanl: The bearing bracket 28 u. Yided With standards 29 cxtenrliru: luminouially thcreiirom. the ends (5 which sci-re 2-. support a cylinder head ":0 oi a cylin er 23K into which the piston rod 27 extend through a stuiling box The piston 1(-l 9.? i pro adapted to be actuaied by means other suitable medium supplied t pipes and 36 to the Valve a. of an Pl'G'.'1iG(l ty e. l; extends to a hcuisuig which 1 ably Secured to the pipe flange 1) cari ioil by the top plate 9 oi the pressure tank. The llQUSlDQ is prorh l with an or x ;ure which is adapted to he closed. WHCU Valve gate l6 is in its chased iiositioiu by mounted on the member 534 fztefiiding from he r or end of the valve gate 16 the arcement being such that before the valve 16 can be opened, the aperture 4.3 of the musing will be exposed, :tor a purpose presently explained. A continuation 46 i the pipe line extends from the housing 42 T-connection 1-7, whereby air unoer the normal operation of the same. 11 .ation at: of the pipe line extends l? to beneath the pressure tank '3, where the same is connected to a check valve e9, which, in turn, is connected to one end of the sand trap 7 mounted at the lower end of the pressure tank 5. A pipe line 50 extends from the sand trap T for the purpose of delirering the m'ried sandand air to the nozzle not shown, of the sand blast apparatus. If desired, there may be interposed in the pipe line 50 an angle fitting 51 for introducing an additional supp of air in an angular direction by means of a pipe line 52 which. is controlled by means or a valve ..uitably located in. said pipe line which pipe line also extends from the source or supply of the air under pressure.

t'lOll (3 is pi'oriiied with an opening which is normall closed by me vns of a plate 55 aecurec over the opening 54. removing; the plate :35, any foreign objects which may hare accnnnila'rcd at the bottom of the pressure tanl: 5 may be readily removed Without dismantling the apparatus.

The op ration of the apparatus may now be readily understood. In the normal functioning; of the same, that is, When the sand b ast is being; sod. at the nozzle, a supply of the sand will be maintained Within the tank 5 and the pressure or the air will, as before stated, he maintained Within the tank by means oi? the Tronnection &7, so that the pressure Within the tank will be substan- Jl lly equal to the pressure in the pipe line from. the source of upply. The air will also pass tl'iroug'h the continuation 3:8 of the pipe check alve alt o prove hlou ing baclr -e pipe line 4L8) the air K the sand trap T noun to those killed in init Ehe sand to ta pressure at a suitable rat conic mixed with. the af and carried alone through. the pipe line 50 to the nozzle, where the sine is used for cleaning (fliiillllgs or other siinilei. operations.

it will sometimes be found, in the operaof the device, that the sand will be ouried in a greater relative quantity than is desired and to overcome tiis condition an he art will per.

additional quantity of air may be injected into the. pipe line 50 by means of the fitting 51 and the air supply pipe 52, which auxiliary supply is controlled. by the valve 53, so that at all times proper conditions of the mixture of air and sand at the nozzle may be secured.

It may here be noted that by the provision of the conical base 6 of the pressure tank 5' the. full capacity of the pressure tank-'5 maybe utilized, and all of the material readily utilized or removed therefrom, which is not the case where a substantially horizontal base on the pressure tank is used, as there will always be in such structures an accumulation of the sand around the sides of the base which cannot be readily removed therefrom.

lLVhen the sand in the pressure tank 5 becomes exhausted, or so diminished in amount that it is desirable to replenish the supply, a suitable quantity of sand is placed within the hopper 13, or has previously been permitted to accumulate therein (that is, where the hopper 13, is located beneath the sandblast room where the discharge nozzle 7 is used) The valve 41 is then closed to prevent the passage of the air under pressure to the pressure tank 5, as well as to the sand trap Air under pressure is now supplied to the front end of the piston 33 within the cylinder 31, which will cause the valve gate 16 to be retracted. Immediately after the movement of thevalve gate 16 con'imences, and before the same has been sufficiently retracted to open the passageway 11 in'tlie valve housing 10, the outlet oi the housin t2, towliich the pipe line 426' is connected, wi i be exposed by the retraction of the closure member li, and the pressure in the tank will thereby be automatically relieved, and blowing back of the sand through the throat 14: at the base of the hopper 13 will be prevented. The valve gate 16 will then continue to be retracted to its open position, and the sand will be permitted to pass through the throat 1st at the base of the per 13 and through the passageway 11 of the housing 10 to the interior of the pressure tank 5. It Will be noted that the throat 1d of the hopper 13 is of adiameter less than the )assageway 11, so that there will be no tendency or likelihood of any foreign objects, such as nails or other materials, becoming fouled within the passageway 11 or on any parts of the valve structure, and the diameter of the throat 1 L being suifieiently large, there will be no tendency for ObSllllllQF tions to gather at that point.

It will be noted that by this arrangement there is provided a tree passage for the sand from the hopper to the interior 0? the pressure tank, and it will also be noted that the operating parts of the vaive are all located outside of the pressure tank and hopper, so that the same are not only removed from the wear caused by'particles of sand getting into the working parts, but the same are also readily accessible "for adjustment and repair, when necessary. 1

Having thus described the nature and characteristic features of my invention, what i claim as new and desire to secure by Letters Patent, is:

1.111 a sand blast apparatus, a pressure tank, a. valve housing mounted thereon hav ing an unobstructed passageway'extending therethrough, a hopper carried by said lionsing having a throat communicating with said passageway, a valve gate adaptedto be moved transversely across said passageway to close the same, externally mounted means "for actuating said valve gate comprising a cylinder, a piston arranged in said cylinder,

and a pistonfrod on which said piston ismounted operatively connected to said valve gate.

2. In a sand blast apparatus, a pressure, tank, a valve housing mounted thereon having an unobstructed passageway extending therethrough, a hopper carried by said housing having a throat communicating with said passageway of less diameter than said passageway, and means adapted to be moved transversely across said passageway to close the same.

in a sand blast apparatus, a pressure tank, a valve housing mounted thereon hav ing an unobstructed passageway extending passageway, a valve gate adapted to be moved transversely across said passageway to close the same, and externally mounted means for actuating said valve gate comprising a cylinder, a piston arranged in said cylinder. and a piston rod on which said piston is mounted operatively connected to saidvalve gate.

In a sand blast apparatus, a pressure tank, a valve housing mounted thereon having an unobstructed passageway extending therethrough, a hopper carried by said housing having a throat communicating with said passageway, a valve gate adapted to be moved transversely across said passageway to close the same, ILIIGELIIS for actuating said valve gate, a sand trap mountec at the bottom of said pressure tank, an air supply pipe line connected to said pressure tank .and to said trap, and means for automatically relieviug t is pressure in the tank when the valve gate is retracted.

(3. In a sand blast apparatus, a pressure tank, a valve housing mounted thereon having an unobstructed passageway extending theretln-ouph, a hopper carried by said housing h ving a throat communicating with said passageway, a valve gate adapted to be moved transversely across said passageway to close the same, mechanism for actuating said valve gate, a sand trap mounted at the bottom of said pressure tank, an air supply pipe line connected to said pressure tank and to said trap, and means for automatically relieving the pressure in the tank when the valve gate is retracted comprising housing interposed in the air supp. line having an out-let aperture, and a member for closing said outlet aperture vuen the valve is in the closed position and exposi the same when the valve gate is retracted, said closure member being operat-ively connected to the valve gate actuating mechanism.

7. In a sand blast apparatus, a pressure tank, a valve housing mounted thereon having an unobstructed passageway extending therethrough, a hopper carried by said housing having a threat communicating with said pass reway, a valve gate adapted to be moved transversely across said passageway to close the same, externally mounted means for actuating said valve gate, a sand trap mounted at the bottom of said pressure tank, an air supply pipe line connected to said pressure tank and to said trap, and means for automatically relieving the pressure in the tank when the valve gate is retracted comprising a housing interposed in the air supply line and having an outlet aperture, and a member for closing said outlet aperture when the valve gate is in the closed position and exposing the same when the valve gate retracted, said closure member being operatively connected. to the valve gate actuating mechanism.

8. In a sand blast apparatus, a pressure tank, a 'alve housing mounted thereon having an unobstructed passageway extending therethroug'h, a hopper carried by said housing havinga throat communicating with said passageway, a valve gate adapted to be moved transversely across said passageway to close the same, externally mounted means for actuating said valve gate comprising a cylinder, a piston arranged in said cylinder, and a piston rod on which said piston is mounted operatively connected to said valve gate, a sand trap mounted at the bottom of said pressure tank, an air supply pipe line connected to said pressure tank and to said trap, and means for automatically relieving' the pressure in the tank when the valve gate is retracted comprising ahousing interposed in the air supply line and having an outlet aperture, and a member "for closing said outlet aperture when the valve gate is in the closed position and exposing the same when the valve gate is retracted, said closure member being operatively connected to the valve gate actuating mechanism.

In testimony whereof, I have hereunto signed my name.

CHARLES Gr. SMITH. 

